Thanks for posting this Wayne! Where did you find it. This is the best quality example of this photo I have ever seen and it answers some questions I have had about the welding process.

The tube is obviously a dud that was used for photographic purposes. The lead wires and gun were not in the tube at the welding stage in production. Guns are installed after the tube is welded.

With the good resolution in this photo, it can be seen how the rotary welding table operated. Just the very edge of the metal ultor rings are exposed for welding. The rotary welding jig has an upper and a lower pressure ring that conceals most of the ultor rings. I always imagined that there was some sort of heat sink protection, and I would imagine the upper and lower pressure rings are probably machined from copper. You can see the rollers on the clamping levers that are used to apply pressure to squeeze the the two halves of the ultor rings together during the welding process.

This is an outstanding photo Wayne! Where did you discover this and are there any more in this series of photos about the 15G?

Thanks,
Bob

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Vacuum tubes are used in Wisconsin to help heat your house.

As their web site explains, they are involved in digitizing newspaper photo archives, which they then sell piecemeal on their site.

There are other similar outfits that I search from time to time, some of which are multiple sites owned by one organization.

Examples:
MMGarchives.com
NewspaperPhotographs.com
JP-TheMint.com

If you get on the email lists, you will find for some of them that they send you links to new sites that they name similarly, but which have content from different times or sources, or may offer images in different price ranges.

I did not see any other photos in this series, but I suggest going to these sites and any others you find and trying more search terms, because you never know what terms the person who wrote the listing will use - it can depend on any terms that happen to appear on the back of the photo as well as the listing writer's thoughts.

__________________www.bretl.com
Old TV literature, New York World's Fair, and other miscellany

"Russell Meredith of Northrop Aircraft perfected the process in 1941. Meredith named the process Heliarc because it used a tungsten electrode arc and helium as a shielding gas, but it is often referred to as tungsten inert gas welding (TIG). The American Welding Society's official term is gas tungsten arc welding (GTAW). Linde Air Products developed a wide range of air-cooled and water-cooled torches, gas lenses to improve shielding, and other accessories that increased the use of the process. Initially, the electrode overheated quickly and, despite tungsten's high melting temperature, particles of tungsten were transferred to the weld. To address this problem, the polarity of the electrode was changed from positive to negative, but the change made it unsuitable for welding many non-ferrous materials. Finally, the development of alternating current units made it possible to stabilize the arc and produce high quality aluminum and magnesium welds."